I think the major features should always be shown somewhere (i.e. for 3.3, 3.4 etc.), with updates and security fixes for smaller point releases added above.

I also found it a bit weird that more 3.3.1 updates were not visible. I didn't mind the 3.3 stuff still being there but the smaller point release updates need to be included too.

As a newbie user, if you were to install WordPress for the first time and it was 3.3.1 and only saw the smaller point release updates then all the 3.3 features would be hidden - which is one good reason for still including them.